Firstly, to understand the way in which polyoma virus causes cellular transformation. To do this we will investigate the functions and subcellular locations of the three T antigens of polyoma virus; the 90,000, 60,000 and 22,000 dalton products of the early region of polyoma. By the use of monospecific antisera and partial purification we hope to be able to define the roles of the individual T antigens in transformation. Secondly, to investigate the mechanism by which 60,000 dalton product of the Rous sarcoma virus src gene product (p60 src) leads to cellular transformation. p60 src possesses protein kinase activity and our efforts will concentrate on identifying phosphorylation of p60 src affects its protein kinase activity.